MakerBot Industries

We’re excited to announce that the latest version of ReplicatorG is now available for download! This version includes a number of under-the-hood improvments, GUI improvements, and one major new feature: stored home positions for Thing-O-Matics. The Z height offset (as well as X and Y) are now stored in the machine’s EEPROM, which means you no longer need to edit your start.gcode whenever your machine height changes.

Here’s a full list of the changes in this release:
New features:
* Print-O-Matic integrated into the GCode generation engine
* Store/recall home position support: No more need to modify start.gcode when your Z height changes.
* Drag & Drop support: drop .stl or .gcode files into ReplicatorG to open them.
* Frostruder support for Thing-O-Matic
* Support for local firmware.xml files (file:// urls)
* Support for internet proxies, using the default Java proxy configuration.
* Added Skeinforge 40, for experimental purposes
* Updates to most core libraries
* Skeinforge 35 is now default
* Wipe commands removed from cupcake profiles
* HPB default temperature lowered to 110 degrees

Bug fixes:
* Rewritten gcode execution engine: fixes many bugs, such as ‘gcode parser is null’
* Homing feedrate specified in machine profile
* Numerous Ultimaker, RaMPS, and RepRap improvements
* Numerous UI tweaks to improve look&feel on OS X

There are a few known issues. In particular, the simulation feature is currently disabled (it’s being replaced with something more awesome), and there are reports that gen3 electronics with stepper extruders aren’t working. We’ll make a point release to address these issues shortly, and if you notice any other ones, please let us know.

Remember magic shell?

I had the opportunity to talk to Nick Starno of MakerBot yesterday regarding something we are both passionate about – getting the best Skeinforge settings to print sweet awesome things. ¹  Nick believes that the “extra shells” setting is the most underlooked and underappreciated settings in all of Skeinforge. ²

Assuming a typical Skeinforge setup, the extruder will first draw the outline of a layer in a part before filling any of it in with more plastic.  That outside trace is the “first shell.”  The “extra shells” setting will add additional interior traces of the outline of the layer for each additional specified.  This picture should explain it better:

2 extra shells, 0 extra shells

Pretend the lines are the paths of the extruder as it lays down plastic.  The figure on the left has the extruder drawing the outline, then draws two extra shells, and then fills the center of the object with plastic.  The figure on the right has the extruder drawing the outline and then filling the object with plastic.³

The “extra shells” setting is probably just as important to part strength and structural integrity as plastic “infill” or the amount of plastic printed inside the object.  It is probably pretty intuitive that an object that is 100% filled with plastic is going to be stronger than an object with 0% filled with plastic.  But what if you don’t need the strongest part possible?  What if you just need an object that is purely decorative, doesn’t need to be strong at all, that just needs to be only just strong enough for a particular application, or prints quickly?

It depends.  Generally speaking, a higher infill ratio will lead to a stronger and sturdier object that will use more plastic and time to print.  Whereas, a lower infill ratio will lead to a lighter, less sturdy object that uses less plastic and time to print.  When I don’t need a part that is super-strong, I typically print with about a 20% fill ratio.  I find this makes for parts that are very strong and durable while still being quick to print without using a ton of plastic.

However, infill isn’t the only concern.  Laying down extra shells can result in an object that is strong on the outside, while still being sparse on the inside.  However, more shells isn’t always better!

• Thin Parts. When you have extra shells on a thin part, a current bug in Skeinforge will cause your thin parts to be hollow.  Basically what’s happening is Skeinforge looks at the thin section of your object, figures that it cannot fit the required number of extra shells in there, and then skips the shells and the infill. ⁴  So, if you’ve got a small or thin part or a part that has small or thin features, you will want to turn extra shells down to 0.
• High Infill. When you have a high infill ratio with insufficient extra shells, the shrinkage that occurs inside the part with the high infill as the plastic cools causes a lot of stress in the printed part.  If the number of extra shells is too low, that stress from too-high of an infill could cause larger volume objects to crack.  Nick has noticed that this effect seem to be worse with smaller diameter nozzles and small layer heights.  I suspect this is a bigger problem for ABS than it is for PLA since PLA has almost no shrinkage, but I haven’t done enough testing to confirm this.

What Skeinforge setting would you like to learn more about?  Leave a comment and let me know!

1. Photo courtesy of *Micky [↩]
2. You can find the “extra shells” settings in Skeinforge here:
   • Fill -> Extra Shells on Alternating Solid Layer (layers)
   • Fill -> Extra Shells on Base (layers)
   • Fill -> Extra Shells on Sparse Layer (layers)

   [↩]

3. Oh, and those sweet sweet awesome drawzwing skillz?  All mine, baby! [↩]
4. Say, for instance, you have a 5mm thick wall and your extruder is laying down 0.5mm wide strands of plastic.  The most extra shells you could fit in there would be 4.  With zero shells, the 5mm thick wall would be composed of a 0.5mm outer perimeter with whatever infill.  With 1 extra shell, you would have the 0.5mm thick perimeter and one 0.5mm shell, with the rest being infill.  With 4 extra shells, you would have a 0.5mm perimeter and four 0.5mm shells, leaving no room for infill.  If you had extra shells at 5 or higher, this bug in Skeinforge would determine that it could not fit in all the shells required, and then just not add shells or infill. [↩]

EEWeb Featured Engineer: Zach Hoeken Smith

EEWeb published an interview with MakerBot co-founder Zach Hoeken Smith as the featured engineer.  Here’s my favorite part:

How did you get into electronics/ engineering and when did you start?

I am not an engineer by education, but it is something that I have picked up through years of designing, building, and playing with mechatronics. Aside from a childhood spent taking everything in sight apart (and occasionally getting it back together again), my real start in engineering was when I got involved in the RepRap project in 2006. I had absolutely no clue about anything, but I was very motivated and spent as much time as I could learning, experimenting, and playing.

Check out the rest of the interview!

Viktors Nyckel (spare key for piggybank) by snrk

What does a MakerBot dad do when his kid loses the key to his piggy bank?  Design and print a new one!

During the winter, my son lost the key for his piggybank. I tried to print a new one this January out of ABS, but that didn’t work. Today, he nagged me for another try, and with a little downsizeing, and PLA in my new Stepstuder, the key actually forced the pigs security system. Big win!

Hurray for snrk, dad and MakerBot hero!

Dalek Edition - Candy Dispenser Topper by TeamTeamUSA

Having known a few Pez dispenser collectors in my time, I have always figured it was just a matter of time before the addiction showed up on Thingiverse. Even better than a model of a Pez dispenser, here’s a thing-post that instructs you how to create “toppers” for existing Pez dispensers using any item on Thingiverse:

The Dalek is just one topper that can be printed using the attached dispenser_insert.stl; virtually any thing on Thingiverse can be turned into a topper with the correct transformations and support material (so sharpen your support-fu)!

As I have been researching support for a week or so, I’m particularly excited about this challenge, and am hunting through Thingiverse for potential candidates.

Dalek Edition - Candy Dispenser Topper by TeamTeamUSA

DISPENSINATE! Show that pesky Davros what his Daleks are really good for - dispensing candy! The Dalek thingiverse.com/download:23816 is just one topper that can be printed using the attached dispenser_insert.stl; virtually any thing on Thingiverse can be turned into a topper with the correct transformations and support material (so sharpen your support-fu)!

This thing brought to you by

Since this weekend’s Memorial Day holiday is the traditional North American start of the grilling season, I was of course scanning Thingiverse for those last-minute BBQ-related prints.  And I was shocked by what I found: more or less nothing!

KitchenAid Mixers get some love, and there are a good number of kitchen-related projects, but this taco holder and beverage opener are just about the only things that seem to have any relation to a BBQ…and the taco holder is a bit of a stretch if you’re not doing a Tex-Mex backyard gathering.  (Ok, here’s a spork, but he’s eating yogurt in the demo – not BBQ-approved.)

So do MakerBotters just not like barbecues?  I was expecting an organizer for grilling tools and some beverage holders, maybe an assembly for a cold-smoker, at least.  Or is the barbecue already a perfect experience that needs no tweaking by DIYers?

I don’t know about you, but I find that tough to swallow.

Round corners for Openscad - Library by WarrantyVoider

Long ago, before “Web 2.0” and the Dot Com crash, the world wide web was kinda ugly.  Most pages were built in HTML using tables, which necessarily meant everything was blocky and boxy looking. ¹  Sure, they were functional, but they weren’t exactly pretty.  After a time new scripts in javascript and cascading stylesheet techniques came into use that allowed web developers to round the corners off square boxes.  Eventually these complicated scripts and piles of nested CSS gave way to more simple and elegant ways to create rounded corners.

That’s what it feels like today, with the release of the OpenSCAD library for rounded corners by WarrantyVoider.  WarrantyVoider has made making a box with rounded corners almost as easy as making a regular box.  Remember this little tidbit from a certain blogger:

1. cube([4,8,16]);

Well, making a rounded cube using this library is as easy as:

1. include <roundCornersCube.scad>
2. roundCornersCube(4,8,16,1);

I think WarrantyVoider has actually gone a long way to helping people make better looking objects that use less plastic.  What’s not to like?!

1. Kinda like a Volvo. [↩]

80 mm tall scan, printed with a Thing-O-Matic

I’ve been working with 3d scanning for over two years now, building my own 3d scanners and writing code to work with commercial scanners like the Kinect. When I started my artist residency at MakerBot, I knew I had to combine 3d scanning and 3d printing. One of the first ideas we had was to set up a 3d photo booth at MakerBot to scan visitors. So I wrote an app called KinectToStl which first launched at the MakerBot NY user group. I modified it a bit based on feedback from that event, and it’s since been fired up for the 3rd Ward Make-A-Thon and Maker Faire Bay Area 2011. Other artists and hackers are exploring the app, like 4nchor5 la6.

I’ve been maintaining a GitHub repository of all the code I write while at MakerBot, and the source is available for download there. If you don’t want to deal with compiling it, there’s also an OSX app available. The project has a few external dependencies that make it slightly difficult to compile right now, primarily because openFrameworks is nearing a release and hasn’t stabilized yet. The source would be most useful for someone interested in recreating this in Processing or another environment.

Once you’ve downloaded the app, plug in your Kinect and start the app, you’ll see three tabs and four sliders.

Screenshot from KinectToStl

The first tab is where the relevant options are:

• zCutoff controls how far away your cutoff plane is, in centimeters. Anything farther than this will disappear into the “background” (flat area).
• fovWidth and fovHeight control the field of view (or angle of view) multiplier in each axis. This acts like a “zoom” function, and lets you zoom into the center of the scan.
• stlSize controls the width of the STL file, in millimeters. I generally stick between 60 and 80 mm.
• useRandomExport is an experimental export option that only works when fovWidth and fovHeight are set to 1. It will attempt to do a more natural triangulation of the model.

Once you’ve framed the subject and have your settings right, click on “exportStl”. This will save an STL file to the /data folder next to the .app. They’re named like screenshots, “Kinect Export 2011-05-25 at 18.21.13.stl” These files are ready to be 3D printed. They’re scaled properly, and sitting flat on the bed. Because they have a high triangle count, they can take anywhere from 10-20 minutes to run through Skeinforge.

The second tab (click in the the second rectangle) is for lighting options if you’re having trouble seeing the live preview. The third tab is for more advanced options. I’ll mention a few:

• temporalBlur is what causes the 3d model to fade over time, and helps with the accuracy of the scan. It’s like the “exposure time” setting on a camera: shorter exposure is noisier, longer is more sensitive to motion but less noisy.
• smoothingAmount controls the level of blurring on the model. This can make a visually more appealing or better skeined model at the expense of loss of detail.
• backOffset controls the size of the backing plane. If you want more layers of backing, turn this up.

I’ve found that the best parameters for printing these models are with 3-4 shells and almost 0 infill. They’ll print quickly like this, and should be fairly structurally sound.

I also recommend playing with the “OSX Kinect Application” posted by CidVilas to Thingiverse, it has a lot more options and a prettier interface.

If you’re interested in scanning an object in a more complete way, I recommend taking multiple STL exports from KinectToStl and doing boolean joins on them after cutting off the backing plane with an intersection operator. If someone tries this out, I’d love to see the results!

All the scans we (myself and MakerBot) have been taking with this app are being posted to the 3dphotobooth Thingiverse account. So if you’ve been to any of the recent events mentioned above, check it out!

Of course you need a tentacle on your wall!  What else would hold your keys for you?  I mean, what do you have, hands?

We aren’t Cthulu-followers or anything, but we do find our intelligent, ocean-dwelling neighbors, the octopi (and other cephalopods) quite charming, so this derivative work by our own schmarty just seems like the perfect thing to have next to your door.

Print eight of them today!

Volumetric Tentacle Key Hook by schmarty

Teennntacllles... coming out of the waaaaallll. amyhurst was asking for a key hook by our front door and decided upon a tentacled theme. guru's awesome volumetric tentacle seemed like a great choice, so I pulled it into OpenSCAD and made space for a 1" roofing nail to slide-and-lock into the back of the tentacle. (thanks to cibomahto for the tagline up top).

This thing brought to you by

Bucket O' Octopi by yeoldebrian

In the tradition of barrel of monkey's these guys are meant to link together en masse. They can form chains or even checkered sheets by connecting on all four corners. This thing was originally conceived and designed by MakerBot's own Matthew Griffin (http://thingiverse.com/mifga). Enjoy and please send comments, we're still working on it! Check out v16 for our latest and greatest version! the sc55 version is the version that they are printing at MakerBot lately....

This thing brought to you by

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